Technical Field
The present disclosure relates to a contact lens product. More particularly, the present disclosure relates to a contact lens product which can prevent myopia or control a progression of myopia.
Description of Related Art
According to the data of World Health Organization (WHO), the prevalence of myopia in all world countries is between 8% and 62%. However, surveys show that the prevalence of myopia in teenagers and children under 18 years old in Taiwan is up to 85%, which is significantly beyond other countries. One reason is probably due to the highly developed 3C electronic devices in recent years, which results in improper stimuluses and overuse of eyes of young children prematurely. Current researches show that once young children suffer early-onset myopia, the degree of myopia will increase with a certain speed. Current researches further show that the lower the age at which the myopia occurs is, the higher probability of becoming high myopia (greater than or equal to 6.0 D) will be. A person suffering high myopia is more likely to further suffer serious complications, such as retinal detachment and glaucoma. Therefore, if a controlling or moderating method can be conducted when the pseudomyopia is observed in the young children, the pseudomyopia can be effectively prevented from becoming myopia, and the high myopia can be further prevented.
The main cause of myopia is a variation of the optical structure of eyeballs. The optical image is mainly affected by the factors, such as cornea, lens and the length of the eyeballs. As for a normal person, lights can be precisely focused on the retina thereof so as to obtain a clearly image. However, as for a person suffering myopia, lights are focused in front of the retina thereof due to an excessive diopter (refractive myopia) or an excessive axial length of the eyeball (axial myopia), so that a blurred image is obtained. Symptoms of myopia of young children can be divided into myopia and pseudomyopia, wherein the myopia occurs due to an excessive axial length of the eyeball and cannot be corrected. However, the pseudomyopia is a temporary symptom caused by excessive tension of ciliary muscle and can be corrected. Clinically, there are many methods for correcting children pseudomyopia. The main methods include wearing orthokeratology and applying long-acting mydriatics. However, the orthokeratology may result in a highly external pressure which makes the wearer uncomfortable. When applying the long-acting mydriatics alone, a higher concentration dose is usually required. Accordingly, the probability of drug side effects is enhanced, too.